Method of imparting permanent crease to fabrics containing free hydroxyl groups



United States Patent US. Cl. 8116.2 20 Claims ABSTRACT OF THE DISCLOSURE A persistent set is imparted to a material produced from yarns or fabrics prepared from fibers containing acidic hydrogen in the repeating structural unit of the fibers by impregnation of the material with an organic bis-sulfonamido aziridine compound and then While mechanically maintaining a desired deformation of the material heating the impregnate at a temperature above 300 F.

This invention relates to a method for imparting permanent set or deformation to certain yarns and fabrics. More particularly, it relates to a method for permanently creasing yarns and fabrics produced from natural fibrous materials or synthetic fiber-forming polymers containing at least one acidic hydrogen per repeating structural unit of the fiber, or, for example, from comparable fiber-forming polymer in which acidic hydrogen is generated as by hydrolysis of pendant ester groups, for example, as in vinylacetate polymers, copolymers and the like. The setting of the yarns and fabrics is effected by interaction at suitable temperatures with polyaziridine compounds of the formula in which R is a polyvalent hydrocarbon radical containing at least two and less than about 35 carbon atoms and in which the bonding of the sulfonamido-aziridine groups to the hydrocarbon radical is primary, i.e., by a primary methyleneic bonding viz,

I CH2 CH S0zN and in which n is at least 2 and less than 5,14, i.e., 2, 3, or 4.

In accordance with the present invention a minor amount of the desired polyaziridine compound is applied to a suitable fabric, for example, cotton cloth; the impregnated cloth is placed in a desired configuration, for example, folded, and heated at a temperature and for a period sufficient to effect chemical interaction between the cloth and the polyaziridine compound. The resulting treated cloth contains an essentially permanent crease or set which persists after repeated launderings.

At least as much as 0.5 weight percent based upon treated cloth is desirably used in order to effectively impart a set. Preferred applications are in the range from about 3 to 15%. Larger amounts can be used, but such use is not particularly advantageous in general in terms of improved set or creasing per additional amount of aziridine setting agent used.

Yarns and fabrics in general which are produced from fiber-forming polymers containing at least one acidic hydrogen per repeating polymer unit are effectively set by the method of the subject invention. Preferred examples are cotton and blends of cotton with synthetic fiber yarns and fabrics. Other examples include vegetable derived fibers, such as kapok, flax, hemp, jute, sisal, bagasse and the like. Also contemplated are yarn and cloth pre- 3,519,381 Patented July 7, 1970 pared from mixtures of polyesters and cotton and the like, for example, mixtures of polyethylene glycol terephthalate and cotton and the like.

By acidic hydrogen is meant hydrogen attached to oxygen as in an alkanol, polyglucose, carboxyl and the like.

Suitable temperatures for effecting the desired interaction between yarn or fabric and the subject polyaziridines are in the range above about 300 F. but below the scorching temperature of the particular material. In general, a temperature in the range from about 300 F. to 450 F. is suitable. At lower temperatures it may be necessary to use a longer heat treating step, i.e., 5-15 minutes, than at higher temperatures.

The crease or deformation forming reaction between the acidic fibrous material and the aziridine functional grouping is catalyzed by strong base, that is to say, by hydroxyl ion. Thus, in general, impregnation of cloth, such as cotton, with a strongly basic aqueous solution, i.e., having a pH of at least about 8, is effective and is sufiiciently basic to promote the desired catalysis. The stronger the base, for example, such as sodium hydroxide, the more efficient is the catalysis. In addition to soluble hydroxides per se, salts of strong bases and Weak acids are also useful because in aqueous medium they hydrolyze, i.e.,

NaA HOH I, NaOH I'IA forming the desired hydroxyl and high pH solution. Soluble carbonate salts are particularly desirable catalyst impregnating solutions for the material to be set. Other useful basic catalysts include quaternary lower alkyl ammonium hydroxides, lower tertiary alkyl amines and the like strong basic amino-compounds which in aqueous solution raise the pH to at least about 8. Dilute aqueous sodium carbonate is preferred. In general, an effective amount of catalyst is from about 0.01 to 0.25 equivalent of base per grams of material to be set.

The application of the subject polyaziridine compounds to the cloth may be accomplished in a variety of ways including aerosol sprays. A clip solution or emulsion of the aziridine compound in a relatively inert volatile hydrocarbon, ketone or even Water or mixtures thereof may be used to impregnate a suitable cloth or yarn. Evaporation of hydrocarbon-like solvents or water may be followed or preceded by application of basic catalyst,

for example, dilute aqueous sodium carbonate as by spraying or dipping and a final heating to set the crease. On the other hand a preferred method is to employ an aqueous emulsion of a bis-aziridine compound in which there is also dissolved an effective amount of basic catalyst compound, for example, based upon the cloth weight from about 0.5 to about 5 weight percent of sodium carbonate, in a single application step followed by drying at a temperature below about 250 F. and eventual heat setting as described above.

The present method is useful for permanently setting or creasing yarn, fibers, cloth and fabricated garments and cloth products such as curtains, drapes, covers and the like. All or part of a suitable garment of cloth fabric may be impregnated depending upon the particular requirement of the occasion. For example, if a single crease is to be set and the area involved represents but a minor portion of a garment, etc., only a corresponding fraction of the item need be impregnated and heated.

On the other hand, aside from the set crease which may be imparted to the treated fabric, no other notable physical effect is apparent upon visual inspection. There fore, it may be more convenient in some instances to impregnate whole cloth, to fabricate the desired article and then to set the desired conformation by heating rather than treat but a minor portion.

To improve the hand of the finished article, it may be, and often is, desirable to include a fabric softener. A preferred type of softener for this purpose is the mono alkyl sulfonylaziridine, e.g., R'SO N(CH CH in which the R group contains 12 to 22 or more carbon atoms. The above described setting action by heat is also effective in applying such softeners.

Polyaziridine compounds in general are useful in the subject invention. At least two sulfonamido-aziridine functional groups are required in order to obtain the desired permanent creasing or set. The bis-aziridines are preferred and most conveniently prepared and used. Higher aziridines, i.e., where n in the aforementioned formula is 3, 4 or more, are effective but usually are less practicable in terms of cost.

Between the sulfonamido-aziridine functional groups there should be at least two carbon atoms. For example, with no carbon atom interposition as in the case of the compound [SO N(CH CH no useful set of fabric is obtainable. On the other hand, mainly for practical reasons, the carbon-atom insulation should not be excessive. Thirty-five carbon atoms appear to be a reasonable maximum. Thus R in the above formula should contain at least two and less than about 36 carbon atoms.

The lower bis-aziridine compounds have an appreciable solubility in water and are also desirably used because of lower cost. Higher molecular weight bis-aziridines, for example, where R is in the range from about C -C have in general little solubility in water but are readily emulsifiable therein and can be conveniently applied to 'cloth in that form.

In the above formula R can be straight chain, branched chain, cyclic, aromatic, olefinic, cycloaliphatic and mixtures thereof. Preferably R is free of olefinic unsaturation (i.e., non-aromatic carbon-carbon double and triple bond unsaturation).

Representative useful polyaziridine compounds are the Pentane-1,5-disulfonic acid Hexane-1,6-disulfonic acid Heptane-1,7-disulfonic acid Octane-1,8-disulfonic acid Nonane-1,9-disulfonic acid B-(4-sulfo-cyclohexyl) ethane sulfonic acid fi-(3-sulfo-cyclohexyl) ethane sulfonic acid 2-butene-1,4-disulfonic acid 3-butene-l,2-disulfonic acid 2,6-octadiene-1,8-disulfonic acid 2,3-divinyl-butane-1,4-disulfonic acid and 2-vinyl-4-hexene-1,6-disulfonic acid Other and higher polyaziridines contemplated include the following compounds:

C6H3 z z z z 2) 13 s 4 2 2 Z 2 2) 2 C 2 2 z z) 4 (CH CH )NO SCH CH[ (CH CH )NO S] CH CH SO N(CH CH and the like.

The examples listed in the table trate the invention.

EXAMPLES 1-21, INCLUSIVE In each of the examples the procedure followed was in general:

(a) The indicated base catalyst was dissolved in water, and a sufiicient weight of solution was uniformly applied to the cloth to provide the specified weight percent of catalyst based upon the weight of fabric used.

(b) The catalyst impregnated cloth swatch was then dried.

(c) The desired bis-aziridine compound was then dissolved in a suitable inert solvent, for example, chloroform, and a sufficient weight of the solution applied to provide the desired amount of the setting agent based upon the weight of the cloth swatch.

(d) The inert carrier solvent was vaporized from the following further illussulfonamido bis-aziridine derivatives of: cloth at a moderate temperature (e) The cloth was folded. Ethane-1,2-d1sulfon1c acid (1) At the temperature and for the period specified Propane-l,3-d1sulfon1c ac1d both sides of the folded swatch were pressed as in the Decane-1,10-d1sulfon1c ac1d ordinary ironing of clothes. (Suitable sensors were used E1cosane-1,20-d1sulfon1c acid to determine the temperature used.) 4-methyl-hexadecane-1,16-d1sulfon1c ac1d (g) The treated swatches were then subjected to a Hexahydro-p-xylylene d1sulfon1c ac1d washing procedure in water at 75 C. for 15 minutes. The Hexahydro-m-xylylene d1sulfon1c ac1d water contained 1.5 weight percent of a commercial alkyl- Butane-1,4-d1sulfon1c ac1d arylsulfonate detergent and 0.1 weight percent of a com- 4-cyclohexyl-6-methylundecane-1,1l-dlsulfonic acid mercial chlorine bleach.

TABLE Percent Curing Percent mono- Pereent N o. of Type of a, w-D1sull'o11a1n1do aziridiaziri- Monoaziricata- Time wash- Crease Ex. eottonwt. d1n0-alkane dine aziridine dine Catalyst lyst T.,F. (min.) ings rating 1 4 oz./yd. oasomwmormh 5 NIMCOJ 0.5 410 1 5 5 5 7;, C4[SO2N(CH2CH2)]2 5 NBJCO: 0.5 380 1 1 5 acron SOzN(CHaCH2)]z 5 M11001 0. 5 380 1 2 5 SO2N(CH1CH2)]1 10 omsolmomom) 4 M11003 1 380 1 5 I 4 5 SO1N(CHzCH2)]z 5 NMCOB 5 520 2 1 2 SOzN(CH1CHz) 1 5 Naicoz 0.5 320 2 1 0 SO1N CHzOH) 5 NZICO; 1.5 320 1 1 1 SOzN(CH2CH2) z 5 N11200:; 1.5 380 1 2 3 SO2N(CH2CH1)]1 5 Nalooa 5 380 1 2 4 SO2N(CH2CHz)]z 5 M11001 1. 5 380 2 2 4 sozNfllHzcHzqz 5 e NanCOz 1.5 380 2 2 4 S0zN(CH2CHz) 1 5 Nalcoa 5 350 1 2 a SOzN(CHzOHg)]z 5 N11200: 5 420 1 2 5 s01 (0111011011 10 NBJCO; 1.5 420 1 2 5 SOzN(CH1CHz)]g 10 NagCO; 1. 5 420 1 2 1 5 SO2N(CH1CH1)]1 10 NazOOa 1.5 420 1 2 5 SOzN(CHzCH2)l2 10 NaOH 0.5 420 1 a 5 sozmoHaormp 1o NBOHI; 0.5 380-340 1 3 5 SOzN(CHzCHz) 7 10 CH2MG3NOH 1 400 1 4 5 so,N(cH,0H1)l1 3 C15SO2N(CH1OH2)] 2 NaOH 0.5 400 4 3 S02N( 2C z)]1 5 C10SO2N(CH:CHz) 5 NaOH 0. 5 400 1 2 4 5 sozN oHloHap 5 NaOH 0.5 380 1 5 5 2a..-. 4 Cs SOzN(CH;CH2) 1 0.5 380 1 5 5 1 Controls lost crease after one washing. 2 A ugle wash was lllSllHlClGllll to distinguish treated from untreated. 3 Feels soft to the touch.

4 Material has a water repellcncy rating of (spray test, AATCC 22-1964). 1 Although having the same crease rating, the C compound produced creases superior to those of the 01 compound.

(h) The washed swatch was rinsed in hot water, dried, visually examined and rated in accordance with the following scale:

Rating No.: Remarks Excellent crease retention. 4 80% crease retention. 3 65% crease retention. 2 50% crease retention. 1 Poor crease retention. 0 No noticeable crease retention.

(i) Item (h) repeated as desired. Rating for multiple washings is final condition of sample.

I claim:

1. Method of imparting a persistent set to a material selected from the group consisting of yarns and fabrics prepared from fibers derived from a fiber-forming polymer containing at least one acidic hydrogen per repeating structural unit of the polymer, said material being selected from the group consisting of cellulosic materials and blends of cellulosic materials with synthetic fibers consisting essentially of impregnating said material based upon the weight thereof with (1) from about 0.5 to 15 percent of a compound of the formula:

R SOzN wherein R is a polyvalent primary hydrocarbon radical having at least two and less than about 36 carbon atoms and n is 2, 3 or 4 and (2) with from about 0.01 to 0.25 equivalent of strong base catalyst per 100 grams of said material and thereafter mechanically deforming said material to form a crease and heating it while maintaining said deformation 'at a temperature in the range above about 300 F. but below the scorching temperature of said material forfa period in the range from about 0.1 to 15 minutes thereby imparting the corresponding crease to said material, said crease being substantially unaffected by ordinary washing.

2. The method as in claim 1 further characterized in that said impregnating with the aziridine is accomplished by applying an aqueous solution or emulsion containing the aziridineto said material and thereafter substantially evaporating the carrier water from said material at temperature below about 300 F.

3. The method as in claim 2 further characterized in that the aqueous medium has dissolved therein said strong base and said evaporation of water carrier is effected at a temperature below about 250 F.

4. The method as in claim 1 further characterized in that the impregnation of the material is accomplished by applying a solution of the aziridine to the material, the solvent being an inert volatile organic diluent.

5. The method as in claim 1 further characterized in that R of said formula is an a,w-polymethylene biradical containing at least 2 and less than about carbon atoms.

6. The method as in claim 1 further characterized in that R of said formula is a saturated hydrocarbon radical.

7. The method as in claim 1 further characterized in that said basic catalyst is selected from the group consisting of alkali metal hydroxides and carbonates.

8. The method as in claim 1 further characterized in that the catalyst is sodium carbonate.

9. The method of imparting a persistent set to a material comprising cotton yarns or fabrics consisting essentially of impregnating said material based upon the weight thereof with (1) from about 0.5 to 15 percent of a compound of the formula:

R SO2N CH2 n wherein R is a polyvalent primary hydrocarbon radical having at least two and less than about 36 carbon atoms and n is 2, 3 or 4 and (2) with from about 0.01 to 0.25 equivalent of strong base catalyst per grams of said material and thereafter mechanically deforming said material to form a crease and heating it while maintaining said deformation at a temperature in the range above about 300 F. but below the scorching temperature of said material for a period in the range from about 0.1 to 15 minutes thereby imparting the corresponding crease to said material, said crease being substantially unaffected by ordinary washing.

10. The method as in claim 9 further characterized in that the impregnating with said aziridine is accomplished by applying an aqueous solution or emulsion containing said polyaziridine to said material and thereafter substantially evaporating the carrier water from said material at a temperature below about 300 F.

11. The method as in claim 9 further characterized in that the aqueous medium has dissolved therein said strong base and said evaporation of water carrier is effected at a temperature below about 250 F.

12. The method as in claim 9 further characterized in that the impregnation of the material is accomplished by applying a solution of the aziridine to the material, the solvent being an inert volatile organic diluent.

13. The method as in claim 9 further characterized in that R of said formula is an a,w-polymethylene biradical containing at least 2 and less than about 10 carbon atoms.

14. The method as in claim 9 further characterized in that R of said formula is a saturated hydrocarbon radical.

15. The method as in claim 9 further characterized in that said basic catalyst is selected from the group consisting of alkali metal hydroxides and carbonates.

16. The method as in claim 9 further characterized in that said catalyst is sodium carbonate.

17. Composition obtained by impregnating cotton cloth with (1) from about 0.5 to 15 weight percent based upon said cloth of a polyaziridine compound of the formula:

R SOzN CH2 n and mixtures thereof wherein R is a primary polyvalent hydrocarbon radical containing at least 2 and less than 35 carbon atoms and wherein n is 2, 3 or 4, and (2) with from about 0.01 to 0.25 equivalent of strong base per 100 grams of said cloth and thereafter mechanically deforming said impregnated cloth to form a crease and heating it while maintaining said crease, said heating being at a temperature in the range above about 300 F. but insufficient to scorch said cloth and for a period in the range from about 0.1 to 15 minutes, thereby imparting to said treated cloth a crease which is substantially unaffected by washing.

18. Composition of claim 17 whereby said deformation is accomplished by folding, thereby producing a permanent crease.

19. The composition of claim 17 wherein at least 3% of said polyaziridine compound is used.

7 8 20. The composition of claim 17 wherein R is a satu- OTHER REFERENCES rated hydrocarbon radical Welch et al.: The Attachment of Active Hydrogen Compounds to Cellulose With Divinyl Sulfone, Tex.

References cued Res. Jour., January 1961, pp. 84-86.

UNITED STATES PATENTS 5 2,327,760 8/1943 Bestian et al. 8ll6.2X HERBERT GUYNN, Prlmary Exammer 2,950,553 8/1960 H1" WitZ X M. HALPERN, Assistant Examiner FOREIGN PAT NTS CL X R 110,652 5/1944 Sweden. 10

64,214 10/1949 Netherlands. 8-115-5,115-7;26239 

